This invention relates to the art of stands and carts for supporting and transporting metal working apparatus and, more particularly, to a device selectively convertible between stand and cart configurations for the latter purpose.
While the present invention finds particular utility in connection with supporting and transporting a power driven threading machine and accordingly will be described in detail in connection therewith, it will be appreciated that the invention is applicable to the supporting and transporting of other metal working machines, such as roll grooving machines as well as machines and devices other than metal working machines.
Collapsible tripod type stands have been provided heretofore for a threading machine as shown for example in U.S. Pat. No. 4,209,274 to Martin, et al. In the latter disclosure, one leg of the tripod is defined in part by a power drive unit for the threading machine, and the other two legs are foldable relative to the one leg between one position in which the three legs and machine are in a tripod configuration and a second position in which the other two legs lie generally parallel to the one leg to facilitate transporting the machine and stand. In this instance, the machine and stand are bodily carried.
Another stand and transporting arrangement for a metal working machine is shown in U.S. Pat. No. 5,718,440 to Roxbury wherein a pipe cutting machine is supported on a tripod stand having foldable legs. The machine is adapted to removably receive a wheeled transportation dolly having support arms interengaged with the chuck and body of the machine. The stand and dolly are manipulated for the wheels to engage an underlying surface, and the legs are folded together so that the stand and machine can be rolled along the underlying surface. A similar stand and transporter assembly is available from The Ridge Tool Company of Elyria, Ohio under the latter""s product designations No. 1206 Stand and No. 32 Transporter. The Stand is a tripod-type stand for supporting a power driven threading machine and has foldable legs for collapsing the stand, and the Transporter comprises an axle bar having wheels on the opposite ends thereof and a mounting bar intermediate the opposite ends and transverse to the axis of the bar. The mounting bar is adapted to be removably received in the chuck jaws of the threading machine, whereby the latter can be supported on an underlying surface by the wheels and moved therealong using the collapsed legs of the stand as a handle unit. The foldable stand is structurally similar to the vise stand shown in U.S. Pat. No. 2,831,583 to Wright, et al.
While stands of the foregoing character serve their intended purpose, they are cumbersome to use and the use thereof is time-consuming with respect to the conversion between the transporter and stand configurations thereof. With regard to the arrangement shown in the Martin, et al. patent, for example, either two people must work together to support the machine and fold the legs, or the user must pivot the unit about two of the legs to position the machine on an underlying surface and then collapse the legs relative to one another. In either event, the machine and stand must be physically lifted and carried from one point of use to another. To erect the machine into the use position thereof, either one person must hold the machine while another unfolds the legs, or the user must unfold the legs to the tripod configuration with the machine on the ground and then physically lift the machine upwardly about the lower ends of two of the legs to the use position. The Ridge Tool Stand and the stand shown in Wright, et al. are also cumbersome to use in that a base component must be lifted and a tray between the legs and defined by articulated plate components must be collapsed upwardly or unfolded downwardly in respectively collapsing and erecting the stand.
While the Roxbury and Ridge Tool Transporter arrangements provide for wheeled transportation of a machine and stand from one location to another, manipulation of the assembly from the transporter to the stand or use position still requires unfolding of the legs of the stand to the tripod configuration thereof and then physically lifting the machine upwardly about the lower ends of two of the legs to reach the use position. Alternatively, the machine can be removed from the stand and remounted thereon after the stand is erected. This is of course very time-consuming and cumbersome. Furthermore, the latter wheeled arrangements require removal of the wheel assembly from the machine before use thereof and, if the latter is a threading machine, mounting or repositioning of the support bars for the die head and mounting of the threading die head thereon. It will be appreciated too that in the latter situation the die head must be transported separately from the threading machine. When it is desired to convert the Roxbury or Ridge Tool stand to the transporter configuration, the die head must be removed, the support rods removed or repositioned and the wheel unit mounted on the machine, and the user must then lower the machine to the underlying surface by pivoting the stand and machine about two of the legs until the wheels engage the underlying surface. Thereafter, the legs of the stand are folded inwardly relative to one another to provide a handle for transporting the wheeled stand. Moreover, the folded legs have to be interengaged with one another such as by a chain wrapped around the legs so as to stabilize the legs against separation from one another during pushing or pulling of the stand.
In accordance with the present invention, a combination cart and stand is provided which minimizes or overcomes the foregoing and other disadvantages of the stands and/or stand and cart combinations heretofore available. In particular in this respect, a cart and stand in accordance with the present invention minimizes the physical work required by a user in lifting and lowering the metal working apparatus mounted thereon in converting from the cart to the stand configuration and vice versa. Moreover, a cart and stand in accordance with the present invention advantageously allows the transporting of a threading machine with the threading die head carriage and support bars in place thereon and enables the conversion between the cart and stand configurations without having to remove or remount the carriage or the support bars therefor on the threading machine. A cart and stand according to the invention comprises a wheeled base and three legs which, in the stand configuration, form a tripod by which a threading machine or other metal working apparatus is supported in a use position spaced above an underlying surface. The foregoing advantages over existing tripod-type stands are achieved in part by providing for one of the legs to be comprised of leg members interconnected for relative displacement between extended and collapsed positions relative to one another and, when in the collapsed position, to be stored relative to the base. The collapsing capability with regard to the one leg allows a user to raise or lower the threading machine relative to the underlying surface in converting between the stand and cart configurations quicker and with less physical effort on the part of the user than is required in connection with initially displacing the prior art wheeled stands between the transporting and use configurations thereof. In particular in this respect, all three legs in the prior art stands are of one piece construction and are rigidly associated with the base portion of the stand when the stand is raised or lowered relative to the underlying surface. Preferably, the leg components of the collapsible leg are biased between the extended and collapsed positions such as by an air spring to further assist a user in lifting and lowering the machine on the base in converting the cart and stand between the two configurations thereof. Preferably, the other two legs in the cart configuration are oriented relative to the base so as to be parallel to one another to provide a pair of spaced apart handles by which the cart can be held in an inclined disposition and rolled along an underlying surface from one location to another.
It is accordingly an outstanding object of the present invention to provide an improved combination wheeled cart and stand for supporting and transporting metal working apparatus.
Another object is the provision of a cart and stand of the foregoing character which requires less physical effort on the part of a user in converting from one to the other of the cart and stand configurations thereof.
Yet another object is the provision of a cart and stand of the foregoing character which is selectively convertible between the cart and stand configurations thereof without having to add or remove component parts in order to use the metal working apparatus in the stand configuration and in order to provide wheels for transporting the apparatus in the cart configuration.
Yet another object is the provision of a cart and stand of the foregoing character in which a leg of the cart and stand has components displaceable between extended and collapsed positions to facilitate converting the cart and stand between the two configurations thereof.
Still a further object is the provision of a cart and stand of the foregoing character wherein the components of the one leg are biased between the extended and collapsed positions thereof in a manner which assists a user in elevating and lowering the metal working apparatus in connection with converting between the cart and stand configurations.